Brake-shoe.



PATENTED JULY 7, 1908.

C. D. PBTTIS.

BRAKE SHOE.

APPLICATION FILED MAR.30, 190B.

3 SHEETS-SHEET l.

y, z 0 7N 6 No. 892,883. PATENTED JULY 7, 1908. G. D. PETTIS.

BRAKE SHOE.

APPLICATION FILED MAR. 30, 1908.

3 SHEETS-SHEET 3.

( 1 a 1 s I d/udw WW5.

1 UNITED STATES PATENT OFFICE.

CLIFTON D. 'PETTIS, OF CHICAGO. ILLINOIS.

BRAKE-SHOE.

Specification of- Letters Patent.

Patented July 7, 1908.

larly tothat class of brake shoes in which a strip or plate of softsteel or like ductile metal is united to the cast iron body of the shoein the casting operation; this type of shoe being commonl designated ascomposite or steel bac shoes.

The object of this invention is to provide a I brake shoe that shallhave not only the advantages incident to the most favored types of comosite shoes now upon the market, ut shall a so possess far greaterstrength and durability than any of such shoes with which ment of theinvention.

1 am familiar:

The invention consists in the features of improvement hereinafterdescribed, illustrated in the accompanyin drawings and particularlypointed out in t e claims at the end of this specification.

The annexed drawings shoe which I regard as the illustrate a brakereferred embodit will be readily understood, however, that individualfeatures of the invention may be em loyed with marked advantage andwithout t e adoption of the structure as an entirety, and that thedetails of structure may be varied without departure from the spirit ofthe invention. Therefore, I do not wish my invention to be understood asrestricted to the precise structure shown, and I shall, therefore, inthe claims at the end of this specification, point out the featureswhich are regarded as'characteristic of my invention.

Figure 1 is' a view in side elevation of a brake shoe embodying myinvention, this shoe being shown as mounted upon a brakehead of theMaster Car Builders type. Fig. 2 is a view in longitudinal section online 2-2 of Fig. 3. 'Fig. 3 is a back view of the brake shoe. thebackplate or skeleton of my improved shoe. Fig. 5 is an enlarged crosssection on line 5-5 of Fig. 2.- Fig. 6 is an enlarged cross section onine 6-6 of Fig. 2. Fi 7 is an enlarged cross section on line 7-7 0 Fig.

Fig. 4 is a detail face view of 2. Fig. 8 is a view in longitudinalsection on line 88 of Fig. 9. Fig. 9 is a face view showing one form oftheback plate, the body of the shoe being indicated in outline. Fig.-

10 is an enlarged view in cross section on line 10-10 of Fig. 8. Figs.11, 12 and 13 are views similar to Figs. 8, 9 and 10, but showing amodified construction embracing features of the invention. largedtransverse section on line 14-14 of Fig.11.

My improved brake shoe comprises a cast metal body 12 and astrengthening back which, preferably, is formed from a single plate ofsoft steel or like ductile metal that will be united with the cast metalbody of the shoe in the castin operation.

' In the preferred orm of the invention illustrated in the drawings, thestrengthening back consists of two side portions 13 and 14, each havingan inwardly extending) flange 15, these side portions 13 and 14 eingunited together centrally by the key lu or loop 16 and at their ends bythe guide several lugs being formed integral with the side portions 13and 14 of the back plate. The side flanges 15 preferably extend from endto end of the back plate of the shoe, these flanges having theirgreatest depth at the center of the shoe and diminishing in Fig. 14 isan'en-- ugs 17, the

thus forming the side flanges 15, the greatest strength is given to theback of the shoe at the center, at which point the most severe strain isimparted to the shoe when the brakes are applied, the strain diminishingfrom the center towards the ends of the shoe. In other words, each ofthe side flanges 15 thus shaped forms a truss with its greatest strengthat the oint of greatest strain. The advantage of tfius shapin the sideflanges will be readily understoo by reference to Fig. 1 of thedrawings, where it will be seen that the brake-head 'A. exerts its mainpressure upon the shoe through its central lugs a that bear upon theback of the shoe at each side of the key lug 16. The flanges 15 of eachof the side portions 13 and 14 are preferably formed or more pointsthroughout their length to permit the cast metal, of which the body ofthe shoe is formed, to flow freely throu h the perforations andinterlock with the anges at opposite. sides thereof. Similarly,perforations 19 are formed at the base of the with perforations 18v attwo tions the cast metal of the body of the shoe will freely flow in thecasting operation. The side portions 13 and 14 are separated by theopening or cut-away space 20 that extends between the end lugs 17 andthis cut-away space 20 is of greatest width adjacent the end lugs anddiminishes in width towards the center of the shoe. The center lug 16and the end lugs 17 are stamped outwardly from the plate and, as shown,the top webs of the side portions 13 and 14 are slit as at 22 so as topermit the side walls of the central lug 16 to rise from points outsidethe inner edges of the side portions 13 and 14. This location of thecentral lug is advantageous in that it brings parts of the side ortions13 and 14 opposite the key B whic unites the brake s oe to the brakeheadA. The angular side portions 13 and 14 are reversely bent or curved,being brought nearest together at the center of the shoe and flaringoutwardly therefrom towards its ends. This reverse bending of the sideortions 13 and 14 is attended with the fol owing, amon other advantages:First, the reverse ben ing of the side portions 13 and 14 brings theouter walls of these side portions sufficiently near to gether at thecenter of the shoe to permit an ample quantity of the cast metal,comprising the body-of the shoe, to flow on the outside of thesesideportions; and, as this metal sets and shrinks after the castingoperation, it

. insures a firmer bond or union between the cast metal and .the backplate of the shoe; second, the reverse bendin of the side portionsproduces a consideraile divergence of the flan es 15 from their centerstowards their en s, and, when the shoe is worn, this gives a width ofcontact surface between the edges of these flanges and the car wheelequal to the altitude of the angle of such divergence measured at thecenter line of the flanges, thereby avoiding any danger of cutting orgrooving a wheel, incident to the contact therewith of a narrow metalplate; third, the reverse bending or divergenoe of the strips or flanges15 causes the central portions of these strips to be brought to Eoints.opposite the central lugs a, of the rake-head and causes the endportions of the strips to be brought opposite the end lugs a of thebrake-head, giving the greati est strength to those portions of the shoeto which the severest and most direct strain is applied. And it isobvious that this reverse bending or divergence of the strips or flanges15 would be advantageous even if the upper parts or side portions 13 and14 were not employed; in other words, a material advantage would resultfrom the employment of reversely bent or diverging p ain or flat stripsset'on edge and so arranged as to exten beneath or at points oppositethe end and central lugs of a brake-head.

have described and illustrated how certain features of the invention maybe employed without its adoption as an entirety, although itwill beobvious that other modifications may be made by the skilled mechanicwhich will embody to a eater or less extent material features of t einvention. The brake shoe above described serves to illustrate, however,what I regard as the preferred .form of the invention in its entirety.

In the preferred manner of forming the back of my improved shoe, a plateof metal is first cut to form the open s ace '20 of materially greaterwidth than t e distance be tween the side portions in the finished shoe;and, by means of suitable dies, the central lug 16 and end lugs 17 arestamped or struck outward, thereby drawing together more closely theside portions 13 and 14, and, as the central lug is formed of greaterheight than the end lugs, the side portions 13 and 14 are drawn moreclosely together at their centers. By the action of the dies, the sideflanges 15 are also formed and a longitudinal curvature is given to theback corresponding in general outline to that desired in the finishedshoe. When the back late has been thus shaped, it will be set within themold and the cast'metal that is to comprise the body of the shoe will bepoured upon it, this metal flowing between and outside of the sideflanges 15 of the back into the open space 20 of the back and throughthe perforations 18 and 19 formed respectively 111 the side flanges 15and in the walls of the central lug 16. If desired, the cast metal maybe allowed to flow into the crown of the end lugs 17, as shown at.24 inFig. 2 of the drawings, although this is not necessary, as the end lugs17 will have ample strength without such reinforcement of cast metal. Ifit is not desired to ermit the metal to flow into the crowns of t e andlugs 17, cores or sand may be placed in such spaces prior to the castingoperation in the same manner as a core or sand would-be filled into thecrown of the central lug 16 as far as the perforations 19. These detailsof the casting operation will be readily understood by those familiarwith the manufacture of composite brake shoes of the type to which myinvention relates.

When the casting operation has been completed, the finished structurewill be as shown in Figs. 1,2, 3, 5., 6, and 7 of the drawings;

that is to say, the cast metal com rising the body of the shoe,"willhave embe ded therein the flanges 15 and top lates of the side gortions13 and 14 and wil extend a slight istance about the side walls of thecentral lug 16 and, if desired, will extend, as at 24,

into the crowns of the end lugs 17 and across the other ends of theselugs, as shown. The

increased strength of the shoe, incident to 65 In a subsequent part ofthis specification I l the features of my invention, will be found toendure throughout the entire life of the shoe, since the inwardlyrejecting flanges 15 will last and will be rmly. interlocked with thecast metal body until the shoe is entirely worn down to the thickness ofthe body portion of the back. In my improved brake shoe, the back thusnot only serves as a most effective means of holding together the castmetal body of the shoe in case of fracture, but, because of the peculiarconstruction of the back, it imparts a far greater degree of rigidity tothe shoe, thus enabling it to resist severe strains, even after a largepart of the cast metal body has been worn away. I

In the modified form of the invention illustrated in Figs. 8, 9 and 10of the drawing s, the structure of the back plate is in the main thesame as that hereinbefore described, but in thisform of the inventionthe 'side portions of the back of the shoe are drawn more nearlytogether and the walls of the central lug 16 extend in line with theside flanges 15 instead of being inset therefrom, as in the form of theinvention illustrated .in the preceding figures of the drawings.

Other modifications of the invention will readily suggest themselves tothose familiar with this type of brake shoe. Thus, in Figs. 11-14 isillustrated a brake shoe in which a strengthening back is formed withinwardly projecting stri s or flan es 15, similar to those hereinbe oredescri ed, and in which the side portions 13 and 14: are connectedtogether ,centrally as at 25, leaving cut-away spaces 26 extendin fromthe central ortion 25 to the raised en lugs 17 of the bac plate.

In this embodiment of the invention, the

strips or flanges 15 are provided with perfo-- ratlons 18 and also withperforations 18 at their centers. The central lug 28 in this lastdescribed shoe, is formed of the cast metal whereof thebody of the shoeis composed. And, informing this shoe, the cast metal is not allowed torun into the e'ndlugs, but open spaces 29 are left beneath the crowns ofsuch lu s as shown in Fig. 14 of the drawings.

- aving thus described my invention, what I claim as new, and desire tosecure b L .ters Patent, is Y 1'. A.-brake shoe of the characterdescribed, comprising a castmetalbody having embedded therein inwardlyprojecting,longitudinal strips, said strips being nearest each other atthe central portion of the shoe and diverging thence towards the ends ofthe shoe. 2. A brake shoe of the character de scribed, comprising a castmetal body having embedded therein reversely bent or diver ing strips,said strips being drawn centralfly toward each other to polnts op ositethe central lugs of the brake-head, an diverging thence to oints o ositethe end In s of the brake-head. j pp Y 3. A brake shoeof the characterdescribed, com rising a cast metal body havin embedded t erein lonitudinal strips, sai strips being nearest eac other at the centralportion of the shoe and divergin towards the. ends of the shoe, saidstrips being united by an integralconnection.

4. A brake shoe of the character described, com rising a cast metal bodyhavin embedded tiierein lon itudinal strips, sai strips being nearesteac other at the central portion of the shoe anddiverging towards theends of the shoe, said strips being united together by integralconnections at their ends and center.

5. A brake shoev of the character described, com rising a cast metalbody havin embedded t erein lon itudinal strips, sai strips beingnearest eac other at the central portion of the .shoe and divergingtowards the ends of the shoe, said strips being united together by oneor more raised lugs integral with said strips.

'6. A brake shoe of the character deembedded therein inwardlyprojecting, longitudinal strips, said strips bein nearest and diver ingthence towards the end of the shoe and being widest at the center anddiminishing towards the end of the shoe.

7. A .brake shoe of the character scribed, comprising a cast metal bodyand a back of' ductile metal having side portions rovided withone ormoreinwardly projectin'g flangeswidest at the center and diminishing towardsthe end of the shoe.

8. A brake shoe of the character described, comprising a cast metal bodyand a back of ductile metal having sideportions provided with inwardlyprojecting flanges extending substantially from end to end of the back,said flanges being nearer each other at the center than at the ends.

9. A brake shoe of the character described, com rising a cast metal bodyhavin embedded tiierein aback of ductile metfi having angular sideprojecting parts of sald side ortions diver ing from the central part oft e shoe towar s the ends thereof; i

10. A brake shoe of the character described, comprising a cast metalbody and a back of ductile metal comprising two longitudinally extendinside portions having inwardly extending anges and a raised central lugformed integral with said side por tions.

scribed, com rising a cast metal body and a back of ductile metalcomprising two, longitudinally extending side portions of angularoutline connected by an offset central lug,

,said si e portions being drawn in about the scribed, comprising a castmetal body having.

each otherat the centralportion o the shoe ortions, the inwardly.

. 1. A brake shoe of the character de said side portions being separatedand form; ing a s ace that is filled by the body metal,

1 tudina ly and centrally to form separate side center and flaringtowards the ends of the shoe.

12. A brake shoe of the character described, comprising a cast metalbody, longitudinally extending side portions or strips embedded in saidcast metal body, and a lug formed integral with said side ortions orstrips, said lug being formed wit 0 enings in its walls to receive thecast meta of the body.

13. A brake shoe of the character described, comprising a body of castmetal having embedded therein a back formed ofa single iece of ductilemetal, cut-away longiportions and having inte ral therewith a raisedcentral lug and raise end lugs.

14. A brake shoe of the character described, comprising a cast metalbody having I embedded therein a strengthening back comprising twolongitudinal bars connected at their centers by an integral lug, saidlug risin from said bars at points nearer the outer si es of the backthan are the opposing edges of said side bars.

15. A brake shoe of the character described, comprising a cast metalbody and a strengthening back of ductile metal, said back being providedwith an-inwardly jecting strip extending longitudinally of the shoe, thecentral portion of said stri being nearest the longitudinal center of te shoe and the end ortions of the strip diverging thence towar s theends ofethe shoe.

CLIFTON D. PETTIS.

Witnesses:

GEO. P. FISHER, Jr., KATHARINE .GERLAOH.

